Backed armchair of tilt type



March 16, 1965 SHOZO NODA BACKED ARMCI-IAIR OF TILT TYPE 3 Sheets-Sheet 1 Filed NOV. 14, 1962 March 16, 1965 51-1020 NODA 3,173,720

BACKED ARMCHAIR 0F TILT TYPE Filed Nov. 14, 1962 3 Sheets-Sheet 2 March 16, 1965 SHOZO NODA 3,173,720

BACKED ARMCHAIR OF TILT TYPE Filed Nov 14, 1962 a Sheets-Sheet :5

6 MM, Kai a/M United States atent 0 3,173,72e BAQKED ARMCHAER 9F TILT TYPE Shozo Nada, 881 Higashi-tanalra, Gotcmba, Japan Filed Nov. 14, 1962, Ser. No. 237,606 2 (Zlaims. (Cl. 297-316) This invention relates to a backed armchair of the tilting type.

It is well known that if a person seated in a backed chair is changed from his normal posture in which his upper torso is upright to his resting posture in which his upper torso is pressed against the back rest of the chair that he can not rest in the chair unless the back rest of the chair is tilted from its upright position toward the rear. When the back rest of the chair is tilted rearward the effect thereof upon the person seated in the same can be further increased by increasing the angle formed between the seat surface of the chair and the surface of the back rest and simultaneously by suitably tilting the seat surface rearward in accordance with the tilt of the back rest of the chair whereby the person more or less lies down in the tilted chair to apply his weight to both the seat and the back rest of the chair. However, when the chair is put in such a tilted state that both surfaces of the seat and back rest are tilted rearward there is not only the possibiliy that the chair will become unstable because the chair including the person seated therein has its center of gravity displaced rearward as compared with the chair in its normal state, but also it is necessary to move forward both the seat and the back rest of tr e chair in accordance with the tilt of the same in order to tilt them without hindrance. Such a measure, however, requires a relatively large space and is unsuitable for use in a limited space such as the interior of a vehicle, an aircraft or the like Where such chairs are to be aligned in rows and columns.

The chief obiect of the invention is to provide an improved backed armchair of the tilting type which is comfortable and capable of being easily tilted with the stability effectively maintained.

With the above object in view, the invention resides in a backed armchair of the tilting type comprising stationary base means, a pair of side leg members mounted at one end on said stationary base means for pivotal movement about an axis transverse to the base means, a tiltable seat unit carried on said pair of side leg members on the other end portion for pivotable movement about an axis transverse to the base means from a normal position in which the upper seat surface is substantially horizontal to a resting position in which the upper seat surface is tilted rearwardly, a tiltable back rest unit connected to said seat unit adjacent the rear end thereof for pivotal movement about an axis transverse to the base meansfroni a normal position in which the back rest extends upward at approximately a right angle to the upper surface of the seat unit to a rest position in which the back rest unit is tilted rearwardly with an angle between the front surface of the same and the upper surface of the seat unit which is greater than a right angle, a drive, means operated by said drive effecting pivotal movement of said pair of side leg members and including means for interlocking said side leg members with said seat unit, a follower member rigidly connected to said bacl; rest unit extending below said seat unit, and means for vertically turning said follower member in accordance with said pivotal movement of said side leg member and hence said seat unit to thereby vary the angle between the seat unit and theback rest unit whereby the armchair can be changed from its normal position in which the back rest unit is substantially at a right angle to the seat unit to its rest position in which both the seat unit and the back rest unit are tilted with angle therebetween greater than a right angle.

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The invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings; in which:

FIG. 1 is a side elevation view of a backed armchair of the tilting type constructed in accordance with the teachings of the invention and illustrated; in its normal position;

FIG. 2 isa viewsimilarto FIG. 1 but illustrating the armchair in its tilted position;

FIG. 3 is a side elevation view, on an enlarged scale, the structural details of the; armchair illustrated inv FIGS. 1 and 2;

FIG. 4 is, a sectional vi w taken on the section line IVIV of FIG. 3;

PEG. 5 is a sectional elevation View taken along line VV of FIG. 4;

FIG. 6 is a plan View of, a transmission system used with the invention; and

FIG. 7 is a wiring diagram of an electric circuit for operating the armchair of the invention Referring now to FXGS. 1 and 2 of the drawings, there is illustrated a backed arnichair of the tilting type constructed in accordance with the teachings of the invention. The backed armchair illustrated comprises a stationary base member 1 adapted to be rigidly secured on a floor of a chamber (not shown) and having at both ends a pair of bearing plates 2 which, in turn, have rotatably mounted thereon near'one; end a horizontal transverse shaft 3. As best shown in- HG. 4,, the bearing plates 2 are upright on the opposite ends of the base plate It at substantially right angles to the plane of the plate and are connected to each ther by a sleeve 24 through which the transverse shaft 3; extends. The shaft 3' the opposite-end portions projecting somewhat beyond the outer faces of the bearing plates 2. and has fixed ly mounted thereon a pair of side legs 4; Tbe-sidelegs 4 have another horizontal transverse'shait 5 rigidly secured to-their opposite ends by nuts. The pair of vertical side legs 4 and the horizontal transverse shafts 3' and 5, constitute a leg framework for the armchair. Pivotably mounted on the shaft S-intermediate the ends are a pair of side beams? extendinglongitudinally of the chairand adjacent the'innersides, of legs 4 respectively; The longitudinal bean-is 7form a lower frame structure for seat unit a of the armchair.

As shown in FIG. 4" a sprocket wheel 8 is loosely mounted on the shaft 3 between the inner face. of each side leg 4- and the; adjacent bearing plate 2' and rigidly secured to-the bearing plate 2 by screws while. another sprocket Wheel 9 is loosely disposed on the shaft 5'between the inner face of the same side leg 4 and the adj acent longitudinal beam 7 and rigidly secured to the beam by screws. The sprocket wheel 8 is vertically aligned with the sprocket wheel 9 and is-connected to it through an endless chain designated by the reference numeral 10 in FIG. 3 and indicated by adotted-and-dashed line connecting both Wheels in FIG. 4. Withthe 'arrangement'as above described it will be appreciated that the pivotal movement of the longitudinalzbeams '7 about the axis of the shafts .eifects pivotal movement of the sprocket wheels 9 and hence theside legs i about the axis of the-.- shaft 3 for a purposewhich will bedescribed'hereinafter.

As more clearly shown in FIGS. 3 and-5, each' of the longitudinal beams. 7'is provided: on the rear end portion (orthe .righthand end. portionas viewed intthesame figures) with apendent projection 12 to which a transverse pivot rod 13 is secured at one end by a set screw 14. Pivotally carried on thepivot rod Band adjaccntboth ends are a pair of support levers 15which are pivotally mounted on the pivot rod-13 by lugs 16 extending upwardly from'thc lower ends of the levers 15. The support levers 15 form a part of a frame structure for a back rest unit 11 of the chair.

It is to be understood that the lower frame structure pivotably mounted on the shaft 5 forms with other frame members (not shown) a frame structure carrying a seat of conventional construction. Similarly, the support levers 15 form with other frame members (not shown) a frame structure carrying a back rest of conventional construction.

The pivot rod 13 also is provided in the middle with a securing projection 17 (see FIG. 4) serving to secure a helical spring 18 at the middle point on the rod 13. That portion of the spring 18 on one side of the middle point is wound around the rod 13 in a direction opposite to the remaining portion thereof with both portions having the same directional characteristics. Both ends of the spring 18 are hooked to rods extending forward from the associated support levers 15 respectively as best shown in FIG. 4. The spring 18 assists in normally maintaining the back rest unit 11 in its normal position in which the unit 11 is substantially upright with respect to the seat unit 6 as illustrated in FIG. 1.

With the arrangement thus far described and if the front end of the seat unit 6 is raised the longitudinal beams 7 are rotated clockwise as viewed in FIGS. 3 and 5 to thereby effect pivotal movement of the sprocket wheel 9 and hence of the side legs 4 about the axis of the shaft 3 in the counterclockwise direction. At the same time, the back rest unit 11 will be tilted toward the rear with the angle between the seat unit and the back rest unit remaining substantially unchanged. On the contrary, when the raised front end of the seat is depressed the side legs 4 and the rest unit 11 will be returned back to their original positions as illustrated in FIG. 1.

According to another feature of the invention the back rest unit 11 is arranged to be automatically tilted rearwardly with respect to the seat unit 6 and in accordance with rearward tilt of the same and vice versa. To this end, a follower arm 19 is provided as a forwardly directed control rod extending from the front end of each support lever 15. It will be seen that, as the seat unit 6 is rearwardly tilted the support levers 15 and hence the follower arm or control rod 19 is gradually lowered while the rod is maintained projecting below the seat unit 6. In order to prevent lowering of the follower arm or control rod 19 and also to turn the same upward or clockwise as viewed in FIGS. 3 and 5, against the action of the spring 18 a horizontal transverse control shaft 34 is rotatably supported on the side legs 4 in such a position that a pair of spaced portions of the same normally contact the follower arms or control rods 19 when the shaft 34 is substantially vertically aligned with the shafts 3 and 5. These portions of the shaft 34 are shown as being contact surfaces 20 in FIGS. 3 through 6. The follower arms or control rods 13 and the contact surfaces 20 of the shaft 34 are designed and arranged such that, as the rearward tilt of the seat unit 6 and the forward tilt of the side legs 4 as previously described proceed the back rest unit 11 can be tilted rearwardly with respect to the seat unit 6 to provide a varying angle between both units determined in accordance with the angle at which the seat unit is tilted rearwardly as will be hereinafter described in detail.

In order to change the armchair from its normal position illustrated in FIG. 1 to its rest position illustrated in FIG. 2 and vice versa, any suitable drive such as a small electric motor and control means therefor can be advantageously disposed in the space left between the pair of opposite side legs, said control means being adapted to be operated by a person seated in the armchair. For this purpose, a mounting member 21 is rigidly secured at one end to a sleeve 22 connecting the longitudinal beams 7 by a set screw 23. As shown in FIG. 4 the shaft 5 extends through the sleeve 22. Also the sleeve 24 as previously described engages a receiving slot 25 formed in the other end of the mounting member 21. Set screws 26 are used 4 to fasten the mounting member 21 to the sleeve 24. Then a small reversible electric motor 27 is suitably mounted on that side of the mounting member 21 facing the front side of the armchair (see FIGS. 1, 2, 3 and 6).

As shown in FIG. 6 the motor 27 includes a rotating shaft 28 on which a sprocket wheel 29 is mounted. The sprocket wheel 29 is operatively coupled by an endless chain 39 to a sprocket wheel 31 mounted on a first transmission shaft 32 which, in turn, is supported in a bearing 33 provided for this purpose. The first transmission shaft 32 has mounted thereon a worm 35 adapted to mesh with a worm wheel 36 mounted on the rotatable control shaft 34 acting as a second transmission shaft. The second transmission shaft 34 also is provided near one end with a pinion 37 which meshes with a toothed sector 38 of relatively large radius pendent from one of the longitudinal beams '7, in this case, the lefthand beam as viewed in FIG. 4.

Further the chair includes on one side in this case the righthand side, an arm rest 39 mounted on a su port arm 40 (see FIG. 4) extending from the same side of the frame structure as the seat unit 6. If desired, the chair may include a pair of arm rests such as 39 on both sides respectively. Longitudinally juxtaposed on the in side portion of the arm rest 39 near the front end are a pair of pushbuttons 41a and 41b for starting the operation of the reversible motor 27 in the forward and reverse directions respectively. Also, as shown in FIG. 5 a pair of limit switches 42a and 42b are provided on the bearing plate 4 disposed on the same side of the chair as the pushbuttons and near the shaft 3 while a contact member 43 is attached to the adjacent side leg 2. The limit switches 43a and 42b and the contact member 43 are positioned such that at the instant the side leg 4 reaches its normal position illustrated the contact member 43 actuates the limit switch 42b whereas at the instant the side leg reaches its resting position as shown in FIG. 2 the contact member actuates the limit switch 42a.

The pushbuttons and the limit switches are connected in an electric circuit for the reversible motor 27 as illustrated in FIG. 7 wherein the circuit is being operated so as to run the motor in the reverse direction or in a direction to return the chair back to its normal state. More specifically, the reversible motor 2'7 includes a rotor R having one end connected to the ground and the other end connected through both a series combination of the normally closed limit switch 42a and the normally open pushbutton 41a and another series combination of the normally closed limit switch 42b and the normally open pushbutton 41b in parallel to the same to a source of power shown as a battery E having a grounded terminal. The motor further includes a field F adapted to be connected between the ground and the other end of the rotor R through a pair of change-over switches CS in a selected sense in accordance with the positions of the latter. The switches CS interlock with both pushbuttons 41a and 41b as shown by broken line in FIG. 7.

For a purpose which will be made clear hereinafter, a bore 44 on the side leg 4 into which the shaft 3 is inserted may preferably be elongated longitudinally of the side leg. In this case, each end portion of the shaft 3 is supported in a bearing 46 disposed between the sprocket wheel 8 and the side leg 4 and adjustably supported by the lower end of the side leg through a screw threaded rod 45 (see FIG. 4). In addition, that portion of the shaft 3 projecting beyond the outer face of the associated side leg 4 is screw threaded and a cap nut 47 threaded on said screw threaded portion is held against the outer face of the side leg whereby the shaft 3 is maintained in place.

The arrangement thus far described is operated as follows: It is now assumed that the chair is to be changed from its normal position illustrated in FIG. 1 to its rest position illustrated in FIG. 2 with the pinion 37 meshing with the toothed sector 38 at the lefthand extremity as shown in FIGS. 3 and 5. Under these circumstances,

the forward pushbutton 41a can be actuated to complete a circuit from the battery. E through the actuated pushbutton 41a and the normally closed limit switch 42s, the rotor R of the motor 27 and the ground back to the battery. Also the field F of the motor is shunted across the rotor G through the pair of change-over switches CS in the reverse positions to those illustrated in FIG. 7. Thus the motor 27 is driven in its forward direction to rotate the pinion 37 in the clockwise direction as viewedin FIGS. 3 and 5 through the elements 29', 3t), 31', 32, 35, 36 and 34. This clockwise rotation of the pinion 37 effects pivotal movement of the toothed sector 38 about the axis of the shaft 5 to tilt the longitudinal beams 7 downwardly resulting in rearward tilt of the seat unit 6. At the same time the sprocket wheels rigidly secured to the longitudinal beams 7 are rotated in the clockwise direction together with the shaft 5 and this effects pivotal movement of the side legs 4 about the axis of the shaft 3 in the counterclockwise direction to tilt the side legs 4 forwardly. As previously described, the support levers for the backrest unit 11 and the follower arms or control rods 1% tend to be lowered simultaneously with the rearward tilt of the longitudinal beams 7. However, the front ends of the follower arms or control rods 19 are prevented from moving downwardly because the said ends contact the contact surfaces 2%] of the shaft 34. Therefore, the follower arms or control rods 19 slide forward on the contact surfaces and are raised against the action of the spring 18. This causes the support levers 15 and hence the back rest unit 11 to be tilted rearwardly with respect to the tilted seat unit 6.

During the movement just described, the rotating pinion 37 continues to travel along the toothed periphery of the sector 38 until the same reaches the other extremity of the sector. At that time, the contact member 5-3 acuates the limit switch 42:: to deenergize and stop the motor. Thus, the components thus moved are brought into and maintained in their positions illustrated by dotted-anddashed line in FIG. 5 and the chair is put in its rest position illustrated in PEG. 2,

If the chair is to be changed from its rest position to its normal position the reverse pushbutton 41b need only to be actuated to operate the various components in the reverse manner to that above described.

It will be appreciated that during the movement of the chair from its normal position to its rest position or vice versa, a person seated on the same can release the actuated pushbutton 41a or 41b to terminate the movement of the chair for the purpose of putting the same in any desired intermediate position in accordance with his physical constitution with the result that the chair is maintained in a stable state in which it is blocked by the Worm and Worm wheel mechanism included in the transmission system.

During long service the chair may functionally fail because of elongation of the endless chains 10. When this occurs, the set screws 26 and the cap nuts 47 can be released to increase the distance between the shafts 3 and 5 and hence the distance between the sprocket wheels 8 and 9 by adjustment of the screw-threaded rod 45' until the endless chains 10 are tensioned. Then the released screws and out are fastened upon the associated members to rigidly maintain the shaft 3 in place.

The invention has several advantages. For example, a chair according to the invention can be changed from its normal position to its rest position in which the surface of a seat unit is suitably tilted rearwardly while the surface of a back rest unit is additionally tilted rearwardly with respect to the surface of the tilted seat unit and in accordance with the degree of tilt of the same in order to put a person seated in the chair into the best rest condition. This tilting movement is effected smoothly by automatic operation of mechanisms disposed within the chair structure so as not to spoil its appearance, this automatic operation being started by a pushbutton. With the chair in its rest position, the side legs for supporting the seat and back rest and are. tilted forwardly and a result both units are displaced forwardly while the tilted back rest unit extends rearwardly. This perman ncreased space longitudinally occupied by the tilted chair to be divided between the front and rear sidesof a stationary base member for tlrechair, whereby the ce'nter of gravity of the chair is substantially prevented from longitudinally moving, In addition, the tilt of the side legs effects lowering of the chair asa wholeleadingto lowering of its center of gravity. This ensures that the chair of the invention is maintained in a stable condition regardless of whether the same is in its normal position or in its rest position.

While the invention has been described in conjunction with one embodiment thereof it is to be understood that various changes in construction and arrangement of the parts may be made without departing from the spirit and scope of the invention.

What I claim is:

1. In a hacked armchair of the tilting type, the combination of stationary base means, a first horizontal trans verse shaft rotatably mounted on said stationary base means, a pair of side leg members rigidly secured to said first rotatable shaft at both ends respectively, a second horizontal transverse shaft rigidly secured at both ends to said pair of side leg members, longitudinal beam means pivotably mounted on said second transverse shaft, and adapted to support a seat unit of the armchair, support means pivotably connected to said longitudinal beam means and adapted to support a back rest unit of the armchair, a pair of sprocket wheels rigidly connected to said stationary base means and said longitudinal beam means respectively, an endless chain operatively coupling said pair of sprocket wheels, a third horizontal transverse shaft rotatably supported at both ends on said pair of side leg members and operatively coupled to said longitudinal beam means, an electric reversible motor coupled to said third shaft for driving said third transverse shaft, control rod means connected to said support means for the back rest unit, said control rod means extending below said longitudinal beam means and having its free end portion slidably engaging said third transverse shaft, and control means coupled to said motor for controlling said electric reversible motor to effect pivotal movement of said longitudinal beam means, whereby the armchair can be displaced from its normal position in which the back rest unit is substantially upright with respect to the seat unit to its rest position in which the armchair is tilted rearwardly with an angle between the seat unit and the back rest unit greater than a right angle and vice versa.

2. In a backed armchair of the tilting type, the combination of stationary base means, a first horizontal transverse shaft rotatably mounted on said stationary base means, a pair of side leg members adjustably mounted on said first rotatable shaft at both ends respectively and adjustable in a direction transverse to the axis of said first shaft, means for adjusting the vertical position of said pair of side leg members relative to said first shaft, a second horizontal transverse shaft rigidly secured at both ends to said pair of side leg members, longitudinal beam means pivotably mounted on said second transverse shaft, and adapted to support a seat unit of the armchair, support means pivotably connected to said longitudinal beam means and adapted to support a back rest unit of the armchair, a pair of sprocket wheels rigidly connected to said stationary base means and said longitudinal beam means respectively, an endless chain operatively coupling said pair of sprocket wheels, a third horizontal transverse shaft rotatably supported at both ends on said pair of side leg members and operatively coupled to said longitudinal beam means, an electric reversible motor coupled to said third shaft for driving said third transverse shaft, control rod means connected to said support means for the backrest unit, said control rod means extending below said longitudinal beam means and having its free end portion slidably engaging said thirdtransverse shaft, and control means coupled to said motor for controlling said electric reversible motor to effect pivotal movement of said longitudinal beam means, whereby the armchair can be displaced from its normal position in which the back rest unit is substantially upright with respect to the seat unit to its rest position in which the armchair is tilted rearwardly with an angle between the seat unit and the References Cited by the Examiner UNITED STATES PATENTS 10/43 Lee 297-342 7/50 Luketa 297-330 4/52 Gray 248-421 3/58 Brundage 297330 7/ 5 9 Feller 24842'1 back rest unit greater than a right angle and vice versa. 10 FRANK B. SHERRY, Primary Examiner. 

1. IN A BACKED ARMCHAIR OF THE TILTING TYPE, THE COMBINATION OF STATIONARY BASE MEANS, A FIRST HORIZONTAL TRANSVERSE SHAFT ROTATABLY MOUNTED ON SAID STATIONARY BASE MEANS, A PAIR OF SIDE LEG MEMBERS RIGIDLY SECURED TO SAID FIRST ROTATABLE SHAFT AT BOTH ENDS RESPECTIVELY, A SECOND HORIZONTAL TRANSVERSE SHAFT RIGIDLY SECURED AT BOTH ENDS TO SAID PAIR OF SIDE LEG MEMBERS, LONGITUDIANL BEAM MEANS PIVOTABLY MOUNTED ON SAID SECOND TRANSVERSE SHAFT, AND ADAPTED TO SUPPORT A SEAT UNIT OF THE ARMCHAIR, SUPPORT MEANS PIVOTABLY CONNECTED TO SAID LONGITUDINAL BEAM MEANS AND ADAPTED TO SUPPORT A BACK REST UNIT OF THE ARMCHAIR, A PAIR OF SPROCKET WHEELS RIGIDLY CONNECTED TO SAID STATIONARY BASE MEANS AND SAID LONGITUDINAL BEAM MEANS RESPECTIVELY, AN ENDLESS CHAIN OPERATIVELY COUPLING SAID PAIR OF SPROCKET WHEELS, A THIRD HORIZONTAL TRANSVERSE SHAFT ROTATABLY SUPPORTED AT BOTH ENDS ON SAID PAIR OF SIDE LEG MEMBERS AND OPERATIVELY COUPLED TO SAID LONGITUDINAL BEAM MEANS, AN ELECTRIC REVERSIBLE MOTOR COUPLED TO 